We are looking at stringing single mode fibre
from utility poles halfway up a mountain in the
Canadian Rocky mountains to connect two buildings.
We would use figure eight cable (integrated

Temperatures vary from +80 F (about 30C) in
summer to -40F (about -35C) in winter. Colder
than this is uncommon but does happen.

Most fibre I've seen is spec'd down to

What happens to fibre when it gets too cold?
And how cold is too cold?

Thanks in advance!